Rock-drill.



Pa'fenced Ian. 30, i900. H. KUCH.

ROCK DRILL.

tion' med July 29, 1899.)

(Applica FIGZ.

. /NVEN 0/'7 (No Model.)

W/T/VESSES NTTE STATES PATENT EEICE.

HENRY KOCH, OF NORTH TARRYTOVN, NEV YORK.

ROCK-DRILL.

SPECIFICATION forming part of Letters Patent No. 642,463, dated January 30, 1900.

Application filed .l'uly 29,1899. Serial No. 725,515. (No model.)

To all whom it may concern.-

Be it known that I, HENRY KOCH, of North A Tarrytown, in the county of Westchester and State of-New York, have invented a new and Improved Rock-Drill, of which the following is a full, clear, and exact description.

This invention relates to that class of drills known as rocker-drills in which the valve is operated directly from the piston; and the object is more effectively to control the feed and exhaust of the steam and to cause the piston to work in such a way as properly to strike the drill upon the work.

This specification is the disclosure of one form of the invention, while the claims define the actual scope thereof.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in both Views.

Figure 1 is a longitudinal sectional view of the invention, showing the piston on the upstroke; and Fig. 2 is asimilar view, except that the piston is shown moving downward and indicating by dotted lines the further downward movement of the piston.

The cylinder 3 carries the steam or other chest 4, from which the steam is fed, and this steam chest communicates with two feedports 5, leading, respectively, toward the ends of the cylinder and communicating with the interior thereof. The upper port terminates slightly below the upper extremity of the cylinder, while the lower feed-port opens into the cylinder at the lower extremity thereof. A steam-pocket is thus formed at the upper end of the cylinder. The cylinder also has exhaust-ports 6, which lead into a chamber 7, which may or may not communicate with the bore of the cylinder. From this chamber the exhaust-nozzle passes.

The piston has a reduced central portion 8, with an upper head 9 and a lower head 10, the heads being joined to the central portion by beveled shoulders 11, which respectively serve to engage the cam surfaces 12 of the rocker 14, which is in the form of a threearm lever and which is carried on a pivot or fulcrum 15. As the piston moves through the cylinder the shoulders 11 engage with the cam-surfaces 12 and throw the rocker back and forth on its pivot 15. Assuming that the piston be moving upward, as in Fig. l, the

shoulder 11 of the head 10 of the piston will strike the lower cam-surface 12 of the rocker 14 and throw the rocker to the position shown by f ull lines in Fig. 2. Then as the piston continues its upward movement the head 10 will engage with and slide along the plain portions 16 of the rocker,thus serving to hold the rocker in the position to which it is thrown until the rocker is shifted by the action of the beveled shoulder 11 of the head 9 of the piston, which takes place when the movement of the piston is reversed. (See dotted lines, Fig. 2.) The steam-chest 4 contains a slide-valve 1 7, with ports 1S respectively communicating with the ports 5 and serving to place said ports alternately in communication with the chest 4 and chamber 7. This slide-valve is engaged loosely with one arm of the rocker 14, so that as the rocker is oscillated the valve 17 is reciprocated in the steam-chest, causing the ports 18 alternately to communicate with the chest 4. With this construction the steam, being always under pressure in the chest 4, is permitted alternately to enter the feedports 5 when the ports 1S of the valve 17 are placed in communication with the chest 4. It will be observed that when one port 1,8 communicates with the chest 4 the other port 18 communicates with the chamber 7 and permits the exhaust-steam to pass into such chamber. Thus the ports 5 alternately act as feed and exhaust ports. The ports 6 act exclusively as exhaust-ports, and hence constitute the principal means of exhaust. shown by the full lines in Fig. l, the steam is being admitted at the lower end of the cylinder and the piston is on the upstroke. When this stroke was first started, the piston was at the bottom of the cylinder and the upper exhaust-port 6 was not covered, thus leaving the steam free to4 exhaust by way of the two upper portsv and "6. As the piston continues upward its head passes over the upper port 6, closing it; but the exhaust still goes on by way of the upper port 5, as shown.

As-shown by full lines in Fig. l, the lower shoulder 11 is just engaged with the lower beveled portion 12 of the rocker 14. As the upward movement of the piston continues the surfaces 11 and 12, engaging with each other, throw the rocker 14 into the position Asl IOO

indicated by dotted lines in Fig. l and full lines in Fig. 2, and then the cylindrical surface of the head l0 engages with the plain portion 16 of the rocker and holds the rocker and valve stationary. The valve 17 being thus thrown', the lower port 5 is closed to steam and opened to exhaust and the upper port 5 is opened to steam. The lower exhaust-port 6 will be uncovered immediately after the lower port 5 is closed to steam. After the closing of the lower port 5 to steam the piston will have a further upward movement, due to its momentum and also to the expansible action of the steam in the lower part of the cylinder; but this movement is iinally checked by the steam-cushion formed at the upper portion of the cylinder and also by the live steam acting against the upper head of the piston. The piston then begins its downward movement, which results in a reversal of the operations above described.

In connection with this construction it will be observed that the exhaust-ports 6 furnish a short passage to the atmosphere, permitting a rapid and eiecting exhaust and also facilitating entry of air into the cylinder after the piston passes the exhaust-ports. (See dotted lines in Fig. 2.) In all drills of this class, owing to the weight of the piston and its attached chuck-rod, the force with which the piston moves, especially on the downstroke, is very great, and this causes the piston to approach nearly to the ends of the cylinder at each stroke. The result is a suction behind the piston at each stroke, and to prevent this from retarding the piston it is necessary to permit the entry of air through the exhaust-ports at the above-specified stages of the operation. Therefore by having the short exhaust-port G leading directly to the open chamber 7 I not only insure rapid and easy exhaustion, but also free circulation of air, all of which is essential to a truly-eftective rockdrill. In this lies one of the important features of my invention.

Having thus described my invention, l claim as new and desire to secure by Letters Pat-ent- 1. A rock-drill, having a cylinder, a steamchest attached to the cylinder, the cylinder having a chamber formed therein, such chamber communicating with the atmosphere and with the interior of the cylinder, the chamber also communicating with the steam-chest, a slide-valve commanding communication between the steam-chest and the said chamber of the cylinder, and the cylinder also having feed ports respectively leading from the steam-chest to the end portions of the cylinder, and exhaust-ports respectively leading from points intermediate the ends of the cylinder and the said chamber, the exhaust-ports communicating with said chamber, a piston working in the cylinder, and means for driving the valve in time with the piston, the said valve serving alternately to place the feedports in communication with the steam-chest and with the said chamber in the cylinder.

2. A rock-drill, having a cylinder formed with a chamber intermediate the ends thereof, the chamber communicating directly with the interior of the cylinder and the cylinder having feed-ports leading respectively to the ends ot the cylinder, and exhaust-ports passing respectively from points intermediate the chamber and the ends of the cylinder and communicating with the chamber, such chamber being in communication with the atmosphere, a valve commanding the feed-ports, means situated within the chamber and connected with the valve, to drive the same, and a piston working within the cylinder and driving such means. A

3.. A rock-drill, having a cylinder formed with a chambertherein, the chamber communicating directly with the interior of the cylinder and with the atmosphere, a steam-chest attached to the cylinder and communicating with the chamber therein, the drill having feed-ports passing from the steam-chest respectively to the ends of the cylinder, and the drill also having exhaust-ports passing from the chamber in the cylinder respectively atpoints intermediate the ends of the cylinder and such chamber, a valve mounted in the steam-chest and serving alternately to open the feed-ports and to connect them with the chamber in the cylinder, means mounted in said chamber for transmitting movement to the valve, and a piston working in the cylinder and actuating said means.

HENRY KOCH.

Vitnesses:

J. WALTER TALMADGE, ARTHUR HAYMAN.

IOO 

